Apparatus for inhibiting spin of railway locomotive wheels during propulsion



Aug. 1, 1961 J. F. FERGUSON APPARATUS FOR INHIBITING SPIN OF RAILWAYLOCOMOTIVE WHEELS DURING PROPULSION 2 Sheets-Sheet 1 Filed July 2, 1959m w m Aug. 1, 1961 J. F. FERGUSON 2,994,564

APPARATUS FOR INHIBITING SPIN OF RAILWAY LOCOMOTIVE WHEELS DURINGPROPULSION Filed July 2, 1959 2 Sheets-Sheet 2 O3 INVENTOR.

Q I; {B Jzmes E frgzzson BY imam a (Zilarney United States Patent2,994,564 APPARATUS FOR INHIBITING SPIN 0F RAILWAY LOCOMOTIVE WHEELSDURING PROPULSION James F. Ferguson, Irwin, Pa., assignor toWestinghouse Air Brake Company, Wilmerding, Pa., a corporation ofPennsylvania Filed July 2, 1959, Ser. No. 824,566 12 Claims. (Cl. 303-2)This invention relates to apparatus for inhibiting spin of railwaylocomotive wheels during propulsion and, more particularly, has relationto control apparatus, including means responsive to spinning or slippingof a locomotive driver wheel caused by excessive propulsion powerapplied thereto, for terminating such spinning or slipping. As usedhereinafter the terms spinning or slipping will apply to that conditionof a wheel whose angular rate of speed, at any given instant, exceedsthe linear rate of speed of the vehicle on which the wheel is mounted.

As is well known, spinning of a vehicle wheel occurs when the propulsionforce applied to said wheel exceeds the resistant force of the tractivefriction between said wheel and the surface on which it is running tothereby overcome said tractive friction and cause the wheel to spin. Onrailway locomotives particularly, spinning of the driver wheels occursfrequently during the starting movement of the train due perhaps to theweight of an especially heavy train or to unfavorable track conditions,or a combination thereof. One of the methods employed heretofore forcorrecting wheel-spin necessitated cutting 011 the propulsion power tothe wheels and sanding the rails to restore traction between the wheelsand rails. By the time traction was restored, the wheels, and thereforethe train, came to or nearly to a standstill. During the interval oftime consumed in correcting the wheel spin the propulsion power remainedcut off, and thus any inertia of movement which the train may haveacquired was, to a large degree, if not completely dissipated during thetime necessary to correct Wheel-spin. It would 'be desirable, therefore,to keep the propulsion power applied to the driver wheels during thetime that occurring wheel-spin is being corrected in order to maintain amaximum inertia of movement under the circumstances.

Accordingly, it is the object of the present invention to provide anapparatus capable of inhibiting or correcting wheel-spin of a locomotivedriver wheel during propulsion thereof and causing said wheel tomaintain or regain full traction without cutting off the propulsiveeffort being applied thereto during the period of wheel-spin correctionand without appreciable loss of inertia of movement already acquired bythe vehicle. More specifically, the apparatus embodying the inventioncomprises electrically operated magnet valve means operable responsivelyto the recognition of a wheel-spin by a wheel-spin sensing circuitassociated with the driving motors of the axles on which the driverwheels are mounted to cause a limited brake application to -be appliedautomatically to the spinning wheel of a predetermined magnitude lessthan a normal brake application but sufiicient for retarding thespinning wheel to the normal rate of rotation of the other wheelswithout cutting off the propulsive power, and for causing saidapplication to be released automatically upon termination of thewheel-spinning condition. The degree of brake application is determinedby the use of a pre-charged, predetermined fluid pressure equalizingvolume the pressure of which acts, upon energization of the magnet valvemeans in response to wheelspin, to pilot operation of a relay valvedevice to efiect supply of fluid pressure to the brake cylinder deviceat a degree in accordance with the pilot pressure. Upon cessation of thewheel-spin, the magnet valve means is deener- Patented Aug. 1, 1961gized and release of the brake application is effected responsivelythereto. In order not to impede normal braking operation at any time,and particularly when initiated -by the engineer during the time thatthe wheel-spin responsive apparatus is operating to correct theoccurring wheel-spin, a double check valve device, which is interposedin the conduit leading to the brake cylinder, operates, when said normalbraking action is initiated, to cut oif any supply of fluid underpressure to the brake cylinder as effected by the wheel-spin responsiveapparatus, and to cut in the supply from the normal source as effectedby the initiation of the normal braking action.

In the accompanying drawings FIG. 1 is a schematic view, with several ofthe component devices sec'tionalized, of the apparatus embodying theinvention, and FIG. 2 is also a schematic view, with several of thecomponent devices sectionalized, of a modified form of the invention, itbeing understood that identical parts in both views are identified withidentical reference numerals.

Description and operation-FIG. 1

As shown in FIG. 1, the wheel-spin inhibiting apparatus embodying theinvention may comprise a brake cylinder device 1 for use in the normalmanner for operating brake shoes (not shown) associated with a vehicledriver wheel (not shown) through any suitable standard type of brakerigging as used on a railway locomotive, for example. The apparatusfurther generally comprises a source of fluid under pressure in the formof a storage reservoir 2, a relay valve device 3 for controlling supplyof fluid under pressure from the reservoir 2 to the brake cylinder 1 andrelease of such pressure from said brake cylinder device, a first magnetvalve device 4, a second magnet valve device 5, an electrical energizingcircuit, generally indicated by the reference numeral 6, for energizingthe magnet valve devices 4 and 5, a wheel-spin sensing circuit generallyindicated by the reference numeral 7 and associated with motors 8 and 9for driving respective axles (not shown) on each of which, at oppositeends, a pair of driver wheels (not shown) is mounted for rotationtherewith, and relay-operated switch means 10 operably controlled bysaid sensing circuit for opening and closing the energizing circuit 7. Agenerator 11, driven in the usual manner as by a diesel engine (notshown), for example, provides the current for driving the motors 8 and9. It should be understood that each driving axle on the locomotive isdriven by a respective motor, but in order to provide an operablewheel-spin sensing circuit (to be immediately described), the axles andtheir respective motors are associated in pairs, each pair beingprovided with a wheel-spin sensing circuit which operates responsivelyto a discrepancy in rate of rotation between the two axles of the pair.

The wheel-spin sensing circuit 7 may be of any suitable type, and theone shown in this instance, for example, is similar to the sensingcircuit shown and described in greater detail in the locomotiveengineers Operating Manual, No. 2300, of the Electro-Motive Division ofGeneral Motors Corporation, La Grange, 111., dated May 15, 1947, fordiesel-electric locomotives. Since reference may be had to theabove-mentioned manual, the sensing circuit 7 and its function will bedescribed herein only to a degree deemed nesessary for an understandingof the invention. In addition to the generator 11 and the motors 8 and9, the sensing circuit 7 also includes respective field coils 12 and 13for said motors, a take-off lead wire 14 from the generator to the fieldcoils, and a return wire 15 from the motors to the generator. The motors8 and 9, with their respective field coils 12 and 13, are connected inthe circuit in parallel relation to each other by wires 16 and 17,respectively. The relay-operated switch means 10 includes a coil 18connected across the wires 16 and 17 by a wire 19, said coil, whenenergized and deenergized, acting to close and open, respectively, aswitch arm 20 for closing and opening the energizing circuit 6, thelatter circuit being provided with a source of power such as a battery21, for example, for energizing the magnet valve devices 4 and 5, thelatter being connected to the former in parallel relation through wires22 and 23 connecting to circuit 6.

The magnet valve device 4, which, with magnet valve device 5, pilotsoperation of the relay valve device 3, cornprises a casing 24 havingformed therein chambers 25, 26, and 27, said chamber 25, in theembodiment of the invention shown in FIG. 1, being connected by aconduit or pipe 28 to a conduit or pipe 29 leading from the reservoir 2.Chamber 26 is connected by a conduit or pipe 30 to an equalizing volume31, said chamber being disposed in the casing 24 intermediate thechambers and 27. A valve 32 is disposed in chamber 27 for controllingcommunication between chambers 26 and 27, and is normally biased by aspring 33 toward a seated position in which communication between saidcham bers is cut off, said valve being operable to an unseated positionin which communication between said chambers is established. Valve 32 isprovided with a fluted stem 34 extending into chamber 26 wherein it isengageable, in abutting relation, with an axially aligned stem 35associated with a valve 36 disposed in chamber 25 for controllingcommunication between chambers 25 and 26. Valve 36 is normally held inan unseated position by the valve stem 34 acting through the valve stem35, in which position communication between chambers 25 and 26, andtherefore between the reservoir 2 and the equalizing volume 31 (throughpipes 29, 28 and is established, said valve being operable, uponenergizetion of a magnet coil (not shown) in the magnet valve device 4,to a seated position in which communication between chambers 25 and 26is cut off and valve 32, by the action of valve stem on stem 34, isoperated to its unseated position above defined.

Magnet valve device 5 comprises a casing 37 in which are formed twochambers 38 and 39, the latter being vented to atmosphere via a port 40formed in the casing wall, while chamber 38 is connected via a conduitor pipe 41 to chamber 27 of the magnet valve device 4. A valve 42 forcontrolling communication between chambers 38 and 39 is normally biasedby a spring 43 toward an unseated position in which chamber 38 is incommunication with chamber 39, and therefore chamber 27 is opened toatmosphere via pipe 41, chamber 39 and vent port 40. Energization of amagnet coil (not shown) in the magnet valve device 5 concurrently withenergization of the coil in magnet valve device 4 causes valve 42 to bemoved to a seated position in which communication between chambers 38and 39 is cut oif. It should be noted that when the energizing circuit 6is closed by switch arm 20, both magnet valve devices 4 and 5, by beingconnected to the same circuit, are energized as above inferred,concurrently to cause concurrent operation of valves 32, 36 and 42 totheir respective positions above defined. It should be pointed out herethat the two magnet valve devices 4 and 5 could be combined into onedevice by incorporating the valve 42 of magnet valve device 5 and itsfunction in the magnet valve device 4. Since the magnet valve devices,

substantially as shown, are standard items of manufacture, the deviceshave been shown separately rather than a single device embodying thefunctions of both.

The relay valve device 3 comprises a casing 44 having therein adiaphragm piston 45 opposingly subjected on opposite sides thereof tofluid pressure in respectively adjacent chambers 46 and 47, the latterbeing connectable, by way of a choke 48 and a conduit or pipe 49, to

the brake cylinder device 1 through a double check valve device 50interposed between said pipe 49 and a conduit or pipe 51 leading to thebrake cylinder. One

end of a cylindrical valve 52 which operates in a bore 52a is coaxiallyconnected to piston 45 on the side adjacent chamber 47, while theopposite end of said cylindrical valve provides an exhaust valve 53encircling an exhaust passageway 54 formed in said cylindrical valve andconstantly open by way of radially formed ports 55 in said cylindricalvalve to an atmospheric vent passageway 56 in the casing.

When fluid pressure in chamber 46 exceeds that in chamber 47, piston 45shifts against resistance of a light bias spring 57 in chamber 47 forsuccessively seating exhaust valve '53 against a supply valve 58 andthen operatively unseating the latter against the force of a lighterbias spring 59. With supply valve 58 unseated fiuid under pressure issupplied from conduit 29 via the supply valve chamber, the annular valveseat for supply valve :58 and slide valve bore 52a to pipe 49 untilpressure in chamber 47 has increased to substantially the pressureprovided in chamber 46, whereupon piston 45 is shifted upwardly, asviewed in the drawing, by spring 57 to a lap position, in which supplyvalve 58 is reseated by spring 59 and exhaust valve 53 is maintainedseated against valve 58, for thereby trapping fluid in the brakecylinder device 1 at a pressure substantially equal to that provided inchamber 46.

A piston 59a hingedly connected to a central boss on the supply valve 58and operating in a bore 59b of the same diameter as the bore 52a of thecylindrical slide valve 52, is preferably provided between spring 59 andthe supply valve 58 so that the supply pressure acting thereoncounterbalances the supply pressure from reservoir 2 acting to seatvalve 58. With the exhaust valve 53 seated on the supply valve 58 andthe supply valve seated in lapped position on its valve seat, the brakecylinder pressure acting on the annular outer seated area of the supplyvalve 58 within the bore 52a is counterbalanced by brake cylinderpressure acting on an equivalent area at the lower side of piston 59aadjacent spring 59 and communicated thereto through a passageway 59cconnecting the bore 52a to the spring chamber at the said lower side ofpiston 59a. Relay valve device 3', although specifically shown anddescribed herein, is illustrative of other forms of relay valve devicessuitable for purposes of the invention claimed herein.

Fluid under pressure is supplied to chamber 46 from equalizing volume31, via a branch conduit or pipe 60 connected to conduit 41, when valve32 in magnet valve device 4 is caused to be unseated by energization ofsaid magnet valve device. When pressure in chamber 46 is reduced, piston45 is biased by spring 57 to a release position in which it is shown inthe drawing and in which exhaust valve 53 is unseated from the thenseated supply valve 58, whereby fluid pressure is released from thebrake cylinder device 1, via conduits 51 and 49 and passageways 54 and56. Thus relay valve device 3 operates to provide fluid pressure in thebrake cylinder device 1 substantially equal to that provided in chamber46 from the equalizing volume 31 via pipe 60.

The double check valve device 50, in addition to being connected to pipe49, is also connected to a conduit or pipe 61 through which fluid underpressure is supplied to the brake cylinder device 1 under normal brakingaction independently of the wheel-spin inhibiting apparatus. The checkvalve device 50, as is well known, is provided with a valve (not shown)which occupies one position or another for selectively permitting flowof fluid under pressure to the brake cylinder device 1 from one or theother of conduits 49 and 61 in accordance with the predominant pressurein the one or the other of said conduits.

Since only a light degree of braking force on the driver wheel isnecessary to terminate wheel-spin, as compared to the degree of brakingforce necessary for retarding or stopping the vehicle during normalbraking action, the degree of fluid pressure supplied to the brakecylinder device '1 by the wheel-spin inhibiting apparatus via pipe 49 isnormally much less than the degree of fluid pressure supplied to saidbrake cylinder via pipe 61 for retarding or stopping the vehicle.Accordingly, when a brake application is initiated by the engineer, theresulting degree of fluid pressure in pipe 61 is always predominantlysufficient for operating the check valve device 50 to open said pipe 61and cut oil pipe 49 to the brake cylinder device 1, notwithstanding thatthe wheel-spin inhibiting apparatus, in response to a concurrentlyoccurring wheel-spin, may have charged pipe 49 with fluid under pressurealso. Of course, in the absence of fluid pressure in pipe 61, thepressure in pipe '49 resulting from operation of the wheel-spininhibiting apparatus in response to an occurring wheel-spin, ispredominantly sufficient for operating the check valve device 50 to cutoff pipe 61 and open pipe 49 to the brake cylinder device 1.

In operation, assuming that, upon application of propulsion power to thedriving axles (not shown) of the locomotive, one pair or set of wheelsmounted on one of the pair of axles driven by the motors 8 and 9 beginsto spin due to some cause such as a wet rail, for example, thewheel-spin inhibiting apparatus operates, as follows, to correct thesituation. Due to the spinning of the one set of wheels, that is, therotation of the one axle at a greater rate than that of the other axleof the designated pair, the output of the motor driving the axle of thespinning wheels exceeds the output of the motor driving the other axle.In other words, assuming that the spinning wheels are the ones on theaxle driven by motor 8, said motor correspondingly gains in speed, ascompared to the speed of motor 9 driving the axle on the non-spinningwheels, to set up a counter electromotive current, and, therefore, anunbalanced flow of current between the two motors. It is this unbalancedflow of current between the two motors 8 and 9 that causes the relaycoil 18 to be energized, since said coil is connected across the twomotor circuits. Energization of coil 18 causes the switch arm 20 toclose the energizing circuit 6 to thereby eflect concurrent energizationof the magnet valve devices 4 and 5.

Upon energization of the magnet valves 4 and 5, valve 36 of magnet valvedevice 4 is moved to its seated position to cut off furthercommunication between reservoir 2 and equalizing volume 31, which is nowcharged with fluid under pressure from said reservoir, and valve 42 ofthe magnet valve device is also moved to its seated position to cut offchamber 27 and chamber 38 from atmosphere. At the same time valve 32 ofmagnet valve device 4 is moved to its unseated position to openequalizing volume 31 to chamber 27 of magnet valve device 4, to chamber38 of magnet valve device 5, to chamber 46 of the relay valve device 3,and to the conduits 41 and 60 leading to chambers 38 and 46,respectively. With fluid pressure in chamber 46 of the relay valvedevice 3, said relay valve device operates, in the manner abovedescribed, to effect supply of fluid to the brake cylinder 1 at apressure substantially equal to that provided in said chamber.

Since, as above noted,,the degree of fluid pressure supplied to thebrake cylinder device 1 for correcting wheelspin is substantially lessthan the degree of pressure that must be supplied to said brake cylinderfor eflecting a retardation or stopping of the vehicle during normalbraking action, the volume of equalizing volume 31 must be predeterminedaccordingly, since said volume is charged from the reservoir 2 which mayalso be the source of fluid under pressure from which said brakecylinder is supplied for normal braking operations. For example, thereservoir 2 may be charged with fluid at 120 p.s.i., the degree requiredfor normal braking operations. Volume 31, therefore, is also chargedwith fluid at 120 p.s.i. at the instant valve 36 of magnet valve device4 moves to its seated position. For purposes of correcting wheel-spin, apressure of 20 p.s.i., for example, may be adequate, and, therefore, thepressure supplied to chantber 46 of the relay valve device 3 should be20 p.s.i. also. With the assumed pressures, the total volume ofequalizing volume 31, pipe 30 and chamber 26, therefore, as comparedwith the total volume of chambers 26, 27, 38 and 46 and of pipes 30, 41and 60, should be one-sixth of the latter, whereby, upon seating ofvalves 36 and 42 and unseating of valve 32, fluid in said equalizingnvolume, pipe 30 and chamber 26 would be expanded six times in volume andreduced to one-sixth its initial pressure, or from p.s.i. to 20 p.s.i.,to act on piston 45 in chamber 46 of the relay valve device 3. Sincepertinent dimensions and specifications, which aifect the installationof the wheel-spin inhibiting ap paratus, may differ among the severaltypes of locomotives on which said apparatus may be used, it is possiblethat the total length and, therefore, total volume of pipes 30, 41 and60 may vary accordingly, in which case it would be desirable to providesome means to compensate for any change in said volume in order tomaintain a desired Volume ratio as just described. Though not shown inthe drawings, an adjustable-volume tuning reservoir, for example,connected to pipe 41 in the embodiment shown in FIG. 1 or to pipe 73 inFIG. 2, could be employed, whereby an appropriate adjustment of thevolume of said timing reservoir would compensate for any variance in thetotal volume of pipes 30, 41 and 60. The relay valve device 3 operates,as above described, to cause fluid from reservoir 2 to be supplied tobrake cylinder device 1 at 20 p.s.i. to terminate wheelspin by retardingthe affected Wheels until their rate of rotation is brought down to thatof the other wheels driven by motor 9. v

When the two axles and, therefore, the two sets of wheels drivenrespectively by the motors 8 and 9 are again rotating at synchronousrates, the discrepancy in current flow between said two motors isterminated, and energization of the relay coil 13 is also terminated.Deenergization of coil 18 effects release of switch arm 20 to open theenergizing circuit 6 and thereby deenergize the magnet valves 4 and 5.When magnet valves 4 and 5 are deenergized, valves 36, 32 and 42 allresume their normal positions, as shown in the drawing. Thus volume 31is again connected to reservoir 2 and charged with fluid under pressuretherefrom, while chambers 27, 38 and 46 are all vented to atmosphere byway of pipes 60 and 41 and past unseated valve 42 through vent port 40.

With chamber 46 of the relay valve device 3 vented to atmosphere, biasspring 57 is effective for shifting piston 45 upwardly, as viewed in thedrawing, to cause successive unseating of exhaust valve 53 from supplyvalve 58, which is then reseated by bias spring 59 to cut oil supply offluid under pressure from pipe 29 to pipe 49. With exhaust valve 53unseated, fluid pressure in the brake cylinder device 1 is vented toatmosphere by way of conduit 51, through check valve device 50, conduit49, and passageways 54 and 56 to terminate retarding action on thewheel.

As was previously explained, any normal braking action initiated duringoperation of the wheel-spin inhibiting apparatus, supersedes the latteroperation by operation of the double check valve device 50.Notwithstanding that the eflect of the wheel-spin inhibiting apparatusis thus cut out, the normal braking action on the spinning wheel is alsoeffective for terminating the spinningcondition of the wheel. It canreadily be seen, therefore, that wheel-spin can be protected against atall times to maintain maximum tractive friction between the wheels andthe running surface of the rails.

Description and 0perati0nFlG. 2

The embodiment of the invention as shown in FIG. 2 differs from that inFIG. 1 by replacing the magnet valve device 5 with a pilot valve device62, which, with magnet valve device 4, pilots operation of relay valvedevice 3, and comprises acasing 63 having thereina diaphragm piston 64and two chambers 65 and 66 adiacent the opposite sides of said piston,respectively. Chamber 65 is connected by a conduit or pipe 67 to chamber26 of the magnet valve device 4. A cylindrical valve 68, which iscoaxially and removably secured to the side of piston 64 adjacentchamber 66, is provided with two axially spaced-apart annular grooves 69and 70. A bias spring 71 disposed in chamber 66 acts to bias piston 64and cylindrical valve 68 toward respective normal positions, in whichgroove 69 registers with an atmospheric port 72 formed in casing 63 andwith a conduit or pipe 73 leading to chamber 46 in relay valve device 3,whereby the latter chamber is open to atmosphere, and in which positionsgroove 70 registers with a branch conduit or pipe 74 connecting withconduit 29 and with a conduit or pipe 75 connecting to the equalizingvolume 31, whereby said volume is charged with fluid under pressure fromreservoir 2. Chamber 66 of pilot valve device 62 is constantly open toatmosphere via a plurality of radial ports 76 and a passageway 77 bothformed in cylindrical valve 68, said passageway opening into the lowerportion of casing 63, as viewed in the drawing, wherein a vent port 78to atmosphere is provided.

Chamber 25 of magnet valve device 4 is open to atmosphere via a ventport 79, and, therefore, conduit 67 and chamber 65 of pilot valve device62 are also open to atmosphere as long as valve 36 is unseated. Chamber27 is connected by a branch conduit or pipe 80 to conduit 29 andfliereby to reservoir 2.

In operation, assuming again that a wheel-spin condition occurs, thesensing circuit 7 operates, as above described, to close the energizingcircuit 6, whereupon the magnet coil of magnet valve device 4 isenergized to cause seating of valve 36 and unseating of valve 32.Chamber 65 of pilot valve device 62 is thus closed to atmosphere andopened to pressure of fluid in reservoir 2 by way of conduits 29, 80 and67. Fluid pressure in chamber 65 causes piston 64 and valve 68 to movedownwardly, as viewed in the drawing, out of their respective normalpositions to respective operative positions, in which groove 70 movesout of registry with pipe 75 to cut 011 volume 31 from conduit 74leading from conduit 29 and reservoir 2, and groove 69 moves out ofregistry with vent port 72 and into registry with conduit 75 to connectconduit 75 and volume 31 to conduit 73 and chamber 46 of relay valvedevice 3.

The relay valve device 3 and the check valve device 50 then operate in amanner similar to that described above in connection with the embodimentof the invention shown in FIG. l to correct the wheel-spin condition.Upon cessation of wheel-spin and restoration of synchronous rotation ofthe two sets of wheels, magnet valve device 4 is deenergized, as abovedescribed, and valve 32 is reseated as valve 36 is unseated. Unseatingof valve 36 efiects venting of chamber 65 of the pilot valve device 62to atmosphere by way of conduit 67, chambers 26 and 25, and vent port79, whereby piston 64 and valve 68 are restored to their respectivenormal positions by spring 71 to cause venting of chamber 46 of therelay valve device 3 for effecting release of fluid pressure from thebrake cylinder 1, as above described.

With valve 68 of the pilot valve device 62 in its normal position,equalizing volume 31 is again charged from reservoir 2 by way ofconduits 29, 74 and 75 in readiness for any subsequent occurrence ofwheel-spin.

As in the case of the embodiment of the invention shown in FIG. 1 and ina manner similar to that described in connection therewith, the checkvalve device 50 is also operative in the second embodiment to permitnormal braking action during such time that the wheel-spin inhibitingapparatus might be in operation. The volume relationship of equalizingvolume 31 with the volumes of conduits 75 and 73 and of chamber 46 ofrelay valve device 3 is established in a manner similar to that setforth in connection with the embodiment shown in FIG, 1 in order tosupply a reduced fluid pressure to the brake cylinder device l forcorrecting wheel-spin as compared to fluid pressure supplied thereto fornormal braking operations.

Having now described the invention, what I claim as new and desire tosecure by Letters Patent is:

1. Apparatus for controlling the spinning of the wheels of a vehicleduring propulsion thereof, said apparatus comprising fluid pressureactuated means for effecting a brake application on the wheels of thevehicle, wheel-spin sensing means, a reservoir normally charged to apredetermined uniform high pressure, a fluid pressure operated relayvalve device having a chamber of predetermined volume and operative uponsupply of fluid under pressure to said chamber to effect supply of fluidat a corresponding pressure to said fluid pressure actuated means, andvalve means controlled by said wheel-spin sensing means for connectingsaid reservoir to said fluid pressure operated relay valve device uponthe occurrence of a spinning condition of the wheels to establish arelatively low uniform operating pressure therefor which is the resultof equalization of the predetermined uniform high pressure from saidreservoir into said chamber.

2. Apparatus as claimed in claim 1 further characterized in that saidvalve means is also effective under the control of said wheel-spinsensing means, while no wheelspin condition exists, to establish acharging communication via which said reservoir is charged to saidpredetermined uniform high pressure and, when a wheel-spin conditionoccurs, to cut off said charging communication.

3. Apparatus for controlling the spinning of the wheels of a vehicle,said apparatus comprising, in combination, fluid pressure actuated meansoperable responsively to a variable degree of fluid pressure foreffecting a degree of brake application on the wheels of the vehiclecorresponding to the degree of fluid pressure supplied thereto, a sourceof fluid under pressure, first valve means operable responsively to apredetermined uniform actuating pressure for causing fluid to besupplied from said source to said fluid pressure actuated means at adegree of pressure corresponding to that of said actuating pressure,wheelspin sensing means, second valve means operable responsively tooperation of said wheel-spin sensing means incident to wheel spinningfor effecting supply of said actuating pressure to said first valvemeans and operable responsively to operation of said wheel-spin sensingmeans incident to termination of said wheel spinning for relieving saidfirst valve means of said actuating pressure, conduit means throughwhich fluid under pressure may be supplied to said fluid pressureactuated means from a source other than said first named source, anddouble check valve means for selectively establishing communicationthrough which fluid under pressure is supplied alternatively from saidfirst named source or from said other source.

4. Wheel-spin inhibiting apparatus for use on railway locomotive havinga plurality of wheel units associated in pairs and normally driven at auniform rate of speed, each wheel unit consisting of a driving axle witha drive wheel mounted at each end for rotation therewith, said apparatuscomprising, in combination, wheel brake-ap' plying means operableresponsively to variable fluid pressure for effecting a degree of brakeapplication on said wheels corresponding to the degree of fluid pressuresupplied thereto, a source of fluid under pressure, relay valve meansoperable responsively to fluid pressure for causing fluid to be suppliedfrom said source to said brake-applying means at a pressurecorresponding to the operating pressure of the relay valve means andoperable responsively to relief of said operating pressure for relievingsaid brake applying means of fluid pressure, electromagnet valve meansoperable, when electrically energized, for effecting supply of fluidunder pressure from 9 l said source to said relay valve means at apreselected uniform pressure and, when electrically deenergized, forrelieving said relay valve means of fluid pressure, an electricalcircuit including a source of electrical energy and effective, whenclosed, for energizing said electromagnet valve means and, when open,for deenergizing the electromagnet valve means, and wheel-spin sensingmeans operable responsively to a discrepancy in rate of speed betweentwo wheel units of a designated pair for causing said electrical circuitto be closed and to termination of said discrepancy in rate of speed,for causing said electrical circuit to be opened.

5. A wheel-spin inhibiting apparatus for use on railway locomotives ofthe type having a plurality of wheel units each consisting of a drivewheel mounted at each end of a driving axle for rotation therewith, saidaxle being driven independently of each other and normally at a uniformrate of speed and being associated in pairs for comparing the rotationalrate of speed between any two axles comprising a designated pair, saidapparatus comprising, in combination, wheel brake-applying meansresponsive to fluid pressure for effecting a brake application accordingto the degree of fluid pressure supplied thereto, a source of fluidunder pressure, conduit means providing for flow of fluid under pressurefrom said source to said brake-applying means, a relay valve deviceinterposed in said conduit means for cont-rolling flow of fluid pressurethrough the conduit means and having provided therein a pressurechamber, self-lapping valve means operable in said relay valve device inone position for permitting flow of fluid pressure through said conduitmeans and in a diflerent position for cutting off such flow of fluidpressure, a piston member in said relay valve device actuableresponsively to a controlled degree of fluid pressure in said pressurechamber to cause operation of said selflapping valve means to its saidone position for permitting supply of fluid to said brake-applying meansfrom said source at a degree corresponding to said piston memberactuating fluid pressure, said piston member being operative forrestoring said self-lapping valve means to its said different positionupon relief of said actuating pressure, a fluid pressure volume chargedfrom said source of fluid under pressure and of predetermined capacityfor providing actuating fluid for said piston member at said controlleddegree of pressure resulting from expansion of said fluid upon releasethereof from said volume to said relay valve device pressure chamber, afirst electromagnet device having associated therewith valve meanshaving a normal position in which said pressure volume is incommunication with said source of fluid under pressure and is cut oflfrom said relay valve device pressure chamber, said first electro-magnetvalve means being operable, upon energization of said firstelectro-magnet valve device, to a different position in which saidcommunication between said source of fluid under pressure and saidpressure volume is cut oh? and a communication between said pressurevolume and said pressure chamber is established, a second electro-magnetdevice having associated therewith valve means having a normal position,in which said pressure chamber is vented to atmosphere and beingoperable, upon energization of said second electromagnet device, to aseated position in which said pressure chamber is closed to atmosphere,an energizing electrical circuit including a source of electrical energyfor concurrently energizing said first and second electro-magnetdevices, when the circuit is closed, to cause concurrent operation ofthe respective associated valve means to their said diflerent and saidseated positions, respectively, and for concurrently deenergizing saidfirst and second electro-magnet devices, when the circuit is open, tocause concurrent restoration of the respective associated valve means totheir respective normal positions, relay-operated switch means forclosing and opening said energizing circuit upon energization anddeenergization, respectively, of a coil associated with said relayoperated switch means, a propulsion motor for each axle in eachdesignated pair of axles, and a wheel-spin sensing circuit includingsaid propulsion motors with said coil connected therein in parallelrelation to said motors, said coil thereby being energizableresponsively to an unbalanced current flow between said propulsionmotors, due to discrepancy in rate of power output therebetween, anddeenergizable upon termination of said discrepancy in rate of poweroutput between said motors.

6. The combination defined in claim 5 further characterized by a doublecheck valve device interposed in said conduit means between the relayvalve device and the brake-applying means, and second conduit meansconnected to said check valve device and through which fluid underpressure may be supplied to said brake-applying means from a sourceother than said first named source and normally at a degree of pressuregreater than said first named source, said double check valve devicecomprising a valve member operable therein for selectively connectingsaid brake-applying means to receive fluid under pressure alternativelyfrom said first named source or from said second conduit means;

7. A wheel-spin inhibiting apparatus for use on railway locomotives ofthe type having a plurality of wheel units each consisting of a drivewheel mounted at each end of a driving axle for rotation therewith, saidaxles being driven independently of each other and normally at a uniformrate of speed and being associated in pairs for comparing the rotationalrate of speed between any two axles comprising a designated pair, saidapparatus comprising, in combination, wheel brake-applying meansresponsive to fluid pressure for eflecting a brake application accordingto the degree of fluid pressure supplied thereto, a source of fluidunder pressure, conduit means providing for flow of fluid under pressurefrom said source to said brake-applying means, a relay valve deviceinterposed in said conduit means for controlling flow of fluid pressurethrough the conduit means and having provided therein a pressurechamber, self-lapping valve means operable in said relay valve device inone position for permitting flow of fluid pressure through said conduitmeans and in a different position for cutting off such flow of fluidpressure, a piston member in said relay valve device actuableresponsively to a controlled degree of fluid pressure in said pressurechamber to cause operation of said self-lapping valve means to its saidone position for permitting supply of fluid to said brake-applying meansfrom said source at a degree corresponding to said piston memberactuating fluid pressure, said piston member being operative forrestoring said self-lapping valve means to its said different positionupon relief of said actuating pressure, a fluid pressure volume chargedfrom said source of fluid under pressure and of predetermined capacityfor providing actuating fluid for said piston member at said controlleddegree of pressure resulting from expansion of said fluid upon releasethereof from said volume to said relay valve device pressure chamber, apilot valve device having associated therewith a valve member having anormal position in which said pressure volume is in communication withsaid source of fluid under pressure and is cut off from said relay valvedevice pressure chamber and said pressure chamber is open to atmosphere,a piston in said pilot valve device operable responsively to fluidpressure from said source in a piston chamber formed in the pilot valvedevice for moving said pilot valve device valve member to an operativeposition in which said communication between said source of fluid underpressure and said pressure volume is cut off, said pressure chamber isclosed to atmosphere, and a communication between said pressure volumeand said pressure chamber is established, an electro-magnet devicehaving associated therewith valve means having a normal position inwhich said piston chamber is vented to atmosphere and being operable,upon energization of the electro-magnet device, to a difierent positionin which said piston chamber is closed to atmosphere and opened to saidsource of fluid under pressure, an energizing electrical circuitincluding a source of electrical energy and effective, when closed, forenergizing said electro-magnet device and, when open, for deenergizingsaid electromagnet device, relay operated switch means for closing andopening said energizing circuit upon energization and deenergization,respectively, of a coil associated with said relay-operated switchmeans, a propulsion motor for each axle inVeach designated pair ofaxles, and a wheel-spin sensing circuit including said propulsion motorswith said coil connected therein in parallel relation to said motors,said coil thereby being energizable responsively to an unbalancedcurrent flow between said propulsion motors, due to a discrepancy inrate of power output therebetween, and deenergizable upon termination ofsaid discrepancy in rate of power output between said motors.

8. The combination defined in claim 7 further characterized by a doublecheck valve device interposed in said conduit means 'between the relayvalve device and the brake-applying means, and second conduit meansconnected to said check valve device and through which fluid underpressure may be supplied to said brake-applying means from a sourceother than said first-named source and normally at a degree of pressuregreater than said first-named source, said double check valve devicecomprising a valve member operable therein for selectively connectingsaid brake-applying means to receive fluid under pressure alternativelyfrom said first-named source or from said second conduit means.

9. Apparatus for controlling the spinning of the Wheels of a vehicleduring propulsion thereof, said apparatus comprising, in combination,fluid pressure actuated means for effecting a brake application on thewheels of a vehicle, a relay valve device comprising a piston actuableresponsively to a certain uniform low pressure to successively causemovement of an exhaust valve to a seated position, in which said fluidpressure actuated means is cut off from atmosphere, and movement of asupply valve to an unseated position in which fluid under pressure isdelivered to said fluid pressure actuated means, said piston beingsubjected to pressurized fluid supplied to said fluid pressure actuatedmeans in opposing relation to said certain uniform low pressure formaintaining said exhaust valve and said supply valve in a lappedposition, whereby the degree of pressure of fluid supplied to saidfluid. pressure actuated means corresponds to the degree ofthe certainuniform low pressure actuating said piston, wheelspin sensing means, andvalve means responsive to operation of said wheel-spin sensing meansincident to spinning of the wheels for supplying actuating fluid to saidpiston at said certain uniform low pressure. 7

10. Apparatus as claimed in claim 9 further characterized in that thesaid valve means is responsive to opera- 12 tion of the said wheel-spinsensing means incident to termination of wheel spinning to ventactuating fluid under pressure from said piston of said relay valve de-'vice.

11. The combination as defined in claim 9 wherein the said valve meanscomprises a first valve device including a valve member therein operableresponsively to said operation of said wheel-spin sensing means incidentto said spinning of the wheels to one position in which actuating fluidis supplied to said piston of said relay valve device and operableresponsively to operation of said wheel-spin sensing means incident totermination of said wheel spinning to a diiferent position in whichsupply of said actuating fluid to said piston of said relay valve deviceis cut ofl, and a second valve device including a valve member thereinoperable concurrently with said first named valve member andresponsively to operation of said wheel-spin sensing means incident towheel spinning to one position, in which an atmospheric communicationfrom said piston of said relay valve device is disestablished, andresponsively to operation of said whereby said actuating fluid may besupplied thereto and vented therefrom, respectively.

12. The combination as defined in claim 9 wherein the said valve meanscomprises a fluid pressure operable pilot valve device having therein apiston operable responsively to fluid pressure for causing movement of avalve member to one position in which actuating fluid is supplied tosaid piston of said relay valve device, said piston of said pilot valvedevice being operative, upon relief of fluid pressure acting thereon, toa normal position for causing movement of said valve member to a normalposition in which supply of said actuating fluid to said relay valvedevice piston is cut off and fluid prmsure acting thereon is vented toatmosphere, and a second valve device having therein a valve memberoperable responsively to operation of said wheel-spin sensing meansincident to wheel spinning to one position in which fluid pressure issupplied to said pilot valve device piston, and operable responsively tooperation of the wheel-spin sensing means incident to termination ofwheel spinning to a diflerent position in which supply of fluid pressureto said pilot valve device piston is cut ofl? and the fluid pressureacting thereon is vented to atmosphere.

'' References Cited in the file of this patent FOREIGN PATENTS 874,639France a May 18, 1942

